This document discusses heterogeneous networks (hetnet) as a solution to the rising demand for mobile data and emphasizes the importance of increasing network capacity while managing coverage and interference issues. It outlines the components of hetnets, including macro, pico, and femto cells, and describes techniques for mitigating intercell interference. The conclusion highlights the need for a multi-tier cellular network approach to enhance data capacity and overall network performance.

1. 1
Presented By :
Suraj Kumar Saini (2015KUEC2015)
Naresh Biloniya (2015KUEC2018)
Indian Institute of information Technology
Kota

2. Table of
Content
 Introduction
 What is Heterogeneous Network (HetNet) ?
 Components of HetNet
 Issues regarding capacity, coverage and interference
 Solutions for the above issues
 Conclusion
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3. Introduction
 The use of mobile devices has been increasing in an exponential
fashion for past few years.
 This forces to increase the capacity of the networks in a dramatic
fashion to meet the upcoming demands.
 The problem is not the coverage – which is now nearly universal – but
the capacity. Because too many users demanding too much data.
3http://nsn.fm/hots/krym-stal-domashnim-regionom

4. In future video traffic will
contribute to 70% of the
total traffic.
29% of traffic will be
because of mobile data.
http://iosappsdevelopments.blogspot.com/2016 4

5. Cellular
networks
 A mobile network that provide services by using a large no. of base stations
with limited power and each covering only a limited area.
 Cellular networks are formed with three main components: Base stations
(BSs), Mobile telephone switching offices (MTSO) and mobile devices.
https://www.slideshare.net/shreb/cellular-network-9803277 5

6. What is HetNet ?
 Heterogeneous is the characteristic of containing dissimilar constituents.
 Heterogeneous Network (HetNet) : A network that consists of a mix of high
power macro cells and low-power nodes, e.g. Pico, Femto cells.
 Mobile experts define a HetNet as a network with complex interoperation
between macrocell, small cell, and in some cases WiFi network elements
 All of them eventually come together to form a larger network as a whole.
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7. Multi-Tier
Networks
 Heterogeneous Network consists of the multiple types of cells.
 Small cells: smaller coverage and capacity.
Small cells consist of :
• Pico-cells
• Femto-cells
• Micro-cells
 Macro cells: larger coverage and capacity.
 Mobile operators mainly use small-cells to extend and maximize their
service coverage and/or to increase the network capacity.
https://www.wilsonpro.com/blog/
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8. Characteristics
of cells
http://www.electronicdesign.com/engineering-essentials/understanding-small
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9. Heterogeneous
Network
http://itresearchreport.blogspot.com/2014/02/heterogeneous-network
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10. Capacity vs.
Coverage
https://www.slideshare.net/Murali007/hetnet
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11. Inter cell
Interference
(ICI)
 Heterogeneous networks require some sort of interference mitigation, since
pico-cells/femto cells and macro-cells are overlapping in many scenarios.
 The main idea of ICIC is to divide each cell into two sections, the cell center
and the cell edge, and then allocate different subcarriers to users in different
locations.
 Practically, it is impossible for subscribers at the edge of two neighboring
cells to use the same frequency.
http://3gppltee.blogspot.in/2012/09/what-is-icic-inter-cell-interference.html 11

12. Inter cell
Interference
Coordination
(ICIC)
Techniques
 There is two types of techniques : FFR & SFR
 Frequency Reuse:
• method to re-use frequencies to increase both coverage and capacity.
 Effective reuse of resources can highly enhance the system capacity
• With a smaller frequency reuse factor (FRF), more available
bandwidth can be obtained by each cell
http://slideplayer.com/slide/9720080/
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13. Fractional Frequency Reuse (FFR):
• The Whole Spectrum band is divided in to W0,W1,W2,W3
• The reason for providing only some part of the spectrum is to avoid the
interference between the neighboring cells (outer region).
• The Spectrum band is not used efficiently in each Femto cell.
Soft Frequency Reuse (SFR):
• The whole spectrum (w0,w1,w2) can be used in each Femto cell.
• The interference between neighboring cells is reduced.
• The Spectrum band is used efficiently in each Femto cell.
https://www.slideserve.com/parry/dynamic
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14. Outdoor
Macro-Pico
Deployment
 Macro cell + Pico cell
 Pico cell(small cells) are deployed over hotzones (ares with high
concentration of UEs)
 This technique provide good benefits :
• Decreasing the load on the macrocell
• Pushing UEs onto lightly loaded picocells where they can
receive more resources
• Transmission power of UEs and base stations can also be
reduced
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15. Continue…
Img source : Research paper
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16. Conclusion
 In this article some facts regarding internet data use are lighted up.
 The article put special emphasis on to increase capacity, coverage
and interference reduction.
 To increase the capacity and coverage of network an approach of
multi-tier cellular network is developed.
 In order to establish the macro, pico and femto cell, interference
creates problem so some techniques are developed for this.
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17. References
 M. Dohler et al., “Is the PHY Layer Dead?,” IEEE Commun. Mag., Apr. 2011.
 V. Chandrasekhar, J. G. Andrews, and A. Gatherer, “Femtocell Networks: A
Survey,” IEEE Commun. Mag., Sept. 2008.
 F. Baccelli and B. Blaszczyszyn, Stochastic Geometry and Wireless Networks,
Foundations and Trends in Networking, 2009.
 H. Dhillon et al., “Modeling and Analysis of K-Tier Downlink Heterogeneous
Cellular Networks,” to appear, IEEE JSAC, Mar. 2011,
http://arxiv.org/abs/1103.2177 .
 A. Ghosh et al., “LTE-Advanced: Next-Generation Wireless broadband
Technology,” IEEE Wireless Commun., vol. 17, no. 3, June 2010, pp. 10–22.
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18. References
Image Courtesy:
 Slide 5,7:
http://iosappsdevelopments.blogspot.com/2014/
http://itresearchreport.blogspot.com/2014/02/heterogeneous-network
 Slide 8,9:
https://www.wilsonpro.com/blog/
http://www.electronicdesign.com/engineering-essentials/understanding-small
 Slide 10,11:
https://www.slideshare.net/Murali007/hetnet
http://3gppltee.blogspot.in/2012/09/what-is-icic-inter-cell-interference.html
 Slide 12,14:
http://ieeexplore.ieee.org/document/6211486/
https://www.slideshare.net/dev464898/ppt-het-net
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19. ThankYou
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